In this paper, a detailed exergetic analysis based on the variation of meteorological parameters was performed for a solar power generation system. All wind and solar energy and exergy characteristics were examined in order to identify the variables that affect the power output of the photovoltaic (PV) system. Atmospheric variables such as air temperature, humidity and wind speed and their effects, shadow effects, tracking losses, and low radiation losses of the PV power output were investigated aiming at identifying the real and net solar energy output. It was shown that some usually disregarded atmospheric variables in planning new PV plants, in fact, do play a significant role on the plant's overall exergetic efficiency as wind chill temperature. The solar potential around a windy coastal hilly area was studied and presented on the basis of field measurements and simulations. Understanding atmospheric parameters variation appears to be of great importance for estimating correctly and trustworthy the energy yield, and special focus was given to that in this paper. Copyright © 2012 John Wiley & Sons, Ltd.